The act of making something shitty or horrible. The act of ruining/damaging something. Used instead of the word ruined or fucked up. This word is used to emphasis how bad things got, the Kitchen table wasn't messy, it was shitified.
Where Tim O'Brien drowned that poor son of a bitch Kiowa for snappin' up his girl. In Vietnam. During the war. See Tim O'Brien's The Things They Carried.
"Tim took a dip in the shitfield on his daughter's 10th birthday."